(a) Field of the Invention
The present invention relates to an improved control system for displacing a personnel carrier attached to a boom and more specifically to a control system which is secured to the personnel carrier and operable by an axially rotatable control handle whereby the carrier may be smoothly displaced in an efficient manner.
(b) Description of Prior Art
Various control systems are known for displacing a personnel carrier which is secured to the end of a boom. The control systems provided in the personnel carrier are lever type systems whereby the displacement of the lever in a particular direction causes the support boom to be displaced and, in turn, the personnel carrier. However, these type of levers do not offer a sensitive type control and by displacing them a small increment, the boom will respond with a quick jerky movement, thereby causing the carrier to be displaced in a likewise manner and often resulting in the operator momentarily losing his balance. Momentary loss of balance causes the operator to further pull on the lever or levers, causing further abrupt movements of the boom and the carrier, and often resulting in injury to the operator.
Another disadvantage of the prior art is that a plurality of these levers are provided, one for moving a boom section in one direction, another for moving the same boom section in an opposite direction and a third for the rotation of the boom. Also, these levers are mounted in a side-by-side relationship in the same plane. Accordingly, the operation of the boom becomes confusing and there is a greater margin for error in the operation of same, which could also result in injury to the operator. As aforementioned, lever controls do not offer delicate precise displacement of the boom and often results in the personnel carrier striking an object which is close by, causing damage to the carrier or the object that it strikes.